The jobs you do to the car, not inside it

What this section covers

Every other section of this site is about the cabin — where you sit, what you plug in, where your phone goes. This one is about the car itself: reading its fault codes, keeping its battery alive, seeing out of it at night, and protecting the paint. Different buyer, different aisle, same standard of evidence.

It exists because these products genuinely did not fit anywhere else. The Roadside section says explicitly that battery maintenance chargers are out of its scope, because a maintainer belongs to somebody storing a car or nursing a failing battery rather than to somebody stranded. That is correct, and it left a real gap. So did diagnostics, lighting, glass and paint.

Diagnostics: the cheapest information you can buy

A check-engine light is a number the car already knows and will not tell you without a reader. A basic OBD2 scanner turns that into a code you can look up before anyone quotes you for the work, and it is the single highest-leverage tool in this section.

The specification to read is not price, it is which systems it can see. A cheap reader handles engine codes only — an ABS or airbag light is invisible to it. The BlueDriver publishes its five supported protocols by name and states that enhanced ABS, SRS and transmission diagnostics work on 13 named brands, which is far more useful than “works on most vehicles”. The scanner page sets out where each tier stops.

Battery care, which is a different job from jump starting

A jump starter gets you moving once. A charger and maintainer stops you needing one. They solve opposite halves of the same problem and people buy the wrong one constantly.

NOCO publishes the chemistries the GENIUS5 supports by name — wet, gel, MF, CA, EFB, AGM and lithium — plus a 120 Ah capacity ceiling and an integrated thermal sensor that adjusts charging to ambient temperature. Those are three checkable figures in a category that mostly says “smart charger”.

Lighting, where the law is the specification

That is not a technicality. A halogen reflector cannot focus an LED emitter correctly, and the result is light scattered into oncoming drivers rather than down the road. We cover the legal routes to a whiter, brighter beam in the headlight bulb guide — and the cheapest real improvement for most people is not a bulb at all, it is clearing a yellowed lens.

Glass and paint

• Wipers are the cheapest visibility upgrade there is, and bracketless beam blades exist for one reason: a framed blade packs with ice and lifts off the glass — best windshield wipers
• Car covers are where breathability beats waterproofing, because a sealed cover on a damp car holds water against the paint — best car covers
• Detailing kits are judged on published contents, and the item that matters most is the grit guard — best car detailing kits
• Jack stands are the one product on this site whose failure mode is a car falling on somebody, and they are ranked accordingly — best jack stands and wheel chocks

How these are ranked

The same way as everything else here. Nothing on this site has been tested by the author, and nothing pretends to be. What each page does instead is compile what the maker publishes, name the standard where one exists — ASME PASE for jack stands, FMVSS 108 for headlamps, DOT and SAE for bulbs — and print “Not published” where a figure is absent, which costs that product points rather than being quietly filled in.

This section has an unusually high proportion of products with real third-party standards attached, which makes it one of the easier parts of the market to buy well in. The full method is on how we research.